FmPower52013-03-07 21:24:04localhostconverted to 1.6 markup42006-07-27 14:42:41devel01.mrc-cbu.cam.ac.uk32006-07-27 14:36:08devel01.mrc-cbu.cam.ac.uk22006-07-27 14:35:58devel01.mrc-cbu.cam.ac.uk12006-07-04 15:00:28Scripting SubsystemUsing a field-map to undistort EPIsBackgroundImprovement in power!Acquiring fieldmapsDownloadWhat you'll need to undistort an EPI data seriesGuide and referenceStep-by-step exampleBatch modeImprovement in power in RFX analysisWhat you really care about is probably power to detect functional activation. Here are the results of a random effects analysis (N=12) of a motor cortex localiser task. Subjects were asked to press a button either with a finger of their left hand (left column) or their right (right column). The data were analysed with or without undistortion. http://imaging.mrc-cbu.cam.ac.uk/images/motortask.gifFunctional images (thresholded at 0.001 uncorrected) are shown superimposed on the SPM T1 template. The numbers in the top left of each image indicate peak t values over the whole volume. After the application of undistortion, clear activation can be seen in motor cortex (BA 4) on each side.